JP3378327B2 - Sheet separation device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention is applied to a facsimile apparatus, a printer or the like, the sheet component that releases documents one by one minute
Regarding the separation device.

[0002]

2. Description of the Related Art Generally, an automatic document feeder for stacking a plurality of documents on a document table and separating the documents one by one in cooperation with a feed roller and a roller pressed against the feed roller is generally used. well known.

One of the major problems in this type of automatic document feeder is that the separation performance varies depending on the document set state of the user. If you show a concrete example,
It has been known that a so-called double feed is likely to occur, in which a stack of a plurality of originals is strongly inserted and the leading end of the original is inserted between the feed roller and the roller that presses against it, so that two or more originals are simultaneously sent. There is.

Therefore, some proposals for solving such a problem have been made. One of them is, for example, in Japanese Patent Laid-Open No. 63-123740 and Japanese Patent Laid-Open No. 3-166128. It is disclosed that a stopper for abutting the leading edge of the document is provided so that the leading edge of the document is aligned at a fixed position during setting. In this way, the leading edge of the document is not inserted between the feed roller and the roller pressed against it, and since the positions of the leading edges are aligned, double feeding can be prevented.

[0005]

However, in the technique described in Japanese Patent Laid-Open No. 3-166128, the shutter torque limiter always generates a torque for raising the stopper while sliding, that is, when the document is fed. The thing is
It is equivalent to the motor always carrying the load of the torque generated by the shutter torque limiter. Therefore, a high output and expensive motor is required, and the torque limiter is constantly slipping during operation, so that durability is also difficult.

An object of the present invention is to solve the above problems and to provide a sheet separating device which is inexpensive and has excellent durability.

[0007]

In order to achieve the above-mentioned object, the present invention provides a separation / conveying means for separating and feeding the sheets one by one from a sheet bundle, and a sheet feeding to the separation / conveying means. A pre-conveying unit which is arranged on the upstream side in the feeding direction and which is in contact with the sheet and conveys the sheet to the separating and conveying unit;
A forward / reverse driving unit for driving the separating / conveying unit and a rotation transmission system for transmitting the rotation of the driving unit are provided, and the separating / conveying unit is driven to rotate the sheet when the driving unit is normally rotated. The sheet separating device for separating and feeding has an inclined surface that abuts on the leading end of the sheet bundle .
One forms the stopper portion side that abuts against the preliminary conveying means in the sheet bundle is aligned by inclining the tip of the sheet bundle so that the state of projecting the feeding direction of the sheet
And a drive transmission unit that is connected to the rotation transmission system and transmits a driving force from the drive unit to the shutter only when the drive unit is rotated in the reverse direction. By reversing the means by a predetermined amount
The shutter is rotated to move the stopper portion to a position where it can be brought into contact with the leading edge of the sheet bundle, and the drive means is normally rotated to release the connection between the rotation transmission system and the drive transmission means. The shutter to the state before turning
Back, characterized in that to release the contact between the sheet bundle and the stopper portion.

Further, the present invention is based on the above-mentioned drive transmission means.
When the driving force is transmitted to the shutter , the driving force regulating means for regulating the transmission of the driving force of a certain level or more to the shutter is provided.

[0009]

With this structure, the shutter is rotated only when the driving means is rotated in the reverse direction so that the stopper portion is brought into contact with the leading end of the sheet bundle and is rotated in the normal direction. The contact state of the sheet bundle is released, and the connection between the rotation transmission system and the drive transmission means is released during normal rotation. Therefore, the drive load when the drive transmission means rotates the drive means in the forward direction. do not become. Also, when the sheet bundle is set, the side of the sheet bundle that is in contact with the preliminary conveyance means is in a protruding state, so that the sheets that are in contact with the preliminary conveyance means are reliably conveyed in order to the separation conveyance means side. be able to.

Further, by rotating the drive shaft in the reverse direction by the specified amount, the stopper projects to a predetermined position on the original table, so that it is not necessary to control the reverse rotation amount very accurately. When it is desired to retract the stopper from the document table during maintenance such as clearing the document jam, it can be retracted from the document table by pressing the shutter with a certain force.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a side view showing the arrangement of rollers and gears according to the first embodiment, where 1 is a feed roller and 2 is a feed roller.
Is a reverse roller, 3 is a pickup roller, 4 is an idle gear, 5 is a drive shaft, 6 is a document table, 7 is a pickup bracket, and 8 is a reverse roller bracket.

As shown in FIG. 1, above the document table 6, a feed roller 1, an idle gear 4, and a pickup roller 3 supported by a pickup bracket 7 are arranged in mesh with each other. A drive gear 5a fixed to the reverse roller 2 and the drive shaft 5 installed on the reverse roller bracket 8 and meshing with the reverse roller 2 is disposed below the. The reverse roller 2 is exposed on the surface of the document table 6 through a hole 6 a formed in the document table 6 and contacts the feed roller 1.

The feed roller 1 is rotated by a drive motor described later, and at the same time, the pickup roller 3 is rotated in the same direction as the feed roller 1 via the idle gear 4. Further, the reverse roller 2 rotates in the same direction as the feed roller 1 when the rotation of a drive motor, which will be described later, is transmitted through the drive gear 5a when the document is fed. for that reason,
A plurality of documents set on the document table 6 are first fed by the pickup roller 3 in the direction A in the drawing, and separated and fed one by one through the nip portion between the feed roller 1 and the reverse roller 2.

FIG. 2 is a perspective view showing the structure near the feed roller, and FIG. 3 is a perspective view showing the structure near the reverse roller.
FIG. 4 is a perspective view showing the appearance of the automatic document feeder. In FIG. 2, 9 indicates a feed roller drive shaft. As shown in FIG. 2, the feed roller drive shaft and the pickup roller 3 are installed on a U-shaped pickup bracket 7. Further, in FIG. 3, reference numeral 10 denotes a one-way clutch, and the one-way clutch 10 is composed of three members, a power input unit 10a, a power transmission unit 10b, and a power output unit 10c.
Reference numeral 11 is a lever standing on the power output portion 10c, 12 is a U-shaped shutter, and 13 is a V-shaped stopper portion formed at both ends of the shutter 12 and arranged on both sides of the pickup bracket 7. .

As shown in FIG. 3, a reverse bracket 8, a power output portion 10c of a one-way clutch 10, a power transmission portion 10b, and a power input portion 10a are installed on the drive shaft 5 in this order, and the power output portion 10c. The lever 11 standing on the
Engage only. Further, the shutter 12 is rotatably installed on the apparatus body.

FIG. 5 is a perspective view showing a drive system according to the first embodiment. Reference numeral 14 is a drive motor, 15 is a feed gear fixed to one end of a feed roller drive shaft 9, and 16 is a fixed end to the drive shaft 5. The reverse gear is shown. As shown in FIG. 5, the drive motor 14 meshes with the feed gear 15, and the feed gear 15 meshes with the reverse gear 16. Therefore, the rotation of the drive motor 14 causes the reverse gear 16 to move to the feed gear.
Interlocks with 15, and rotates in reverse with respect to the feed gear 15. The feed roller 1 (see FIG. 1) receives a rotational force directly from the feed roller drive shaft 9, and the reverse roller 2 (see FIG. 1) receives a rotational force via the drive gear 5a. The roller 2 rotates in the same direction.

FIG. 6 is a plan view showing the structure of the one-way clutch according to the first embodiment. 10d is a ratchet part formed between the power input part 10a and the power transmission part 10b, and 10e is a power transmission part. 10b is a protrusion standing from the surface facing the power output portion 10c, and 10f is a sliding surface formed on the power transmitting portion 10c facing the power transmission portion 10b. The sliding surface 10f is inclined from the left side to the right side in FIG. In addition, this sliding surface 10f
The tip of the protrusion 10e comes into contact with. Reference numeral 10g indicates locking portions formed on both sides of the sliding surface 10f.

The above-mentioned power input portion 10a is fixed to the drive shaft 5, the power transmission portion 10b is fitted into the drive shaft 5 so as to be movable in the axial direction and the circumferential direction, and the power output portion 10c is in the circumferential direction. It is inserted so that it can only be moved to. Further, the ratchet portion 10d is configured such that the right upwardly facing tooth molds mesh with each other, as shown in the figure.

Therefore, when the drive shaft 5 is rotated in the direction B in the figure, the ratchet portion 10d meshes with the power transmission portion 10b to rotate, and the projection 10e engages with the locking portion 10g so that the power output portion. 10c also rotates in the direction of B in the figure in conjunction with it. When the drive shaft 5 is rotated in the C direction in the drawing, the ratchet portion 10d is disengaged, and at the same time, the power transmission portion 10b moves in the axial direction while the projection 10e slides on the sliding surface 10f. Therefore, the rotational force is not transmitted to the power output portion 10c via the protrusion 10e, and only the drive shaft 5 rotates.

By the way, the pickup roller 3 is located away from the original table 6 by the operation of a solenoid or the like (not shown) when there is no original on the original table 6, and when the original is set, the original is detected by a sensor or the like. It is detected, rotates about the axis of the feed roller 1, and descends as shown in FIG. Then, the uppermost original is conveyed in the direction of the feed roller 1.

FIG. 7 is a plan view showing a state where the ratchet portion is engaged, and FIG. 8 is a plan view showing a state where the ratchet portion is disengaged.

When the drive shaft 5 is rotated in the direction C in the figure, the ratchet portion 10d is disengaged as shown in FIG. 8, and the reverse roller 2 reverses to the original feeding direction via the drive gear 5a. Rotate in the direction. Further, when the drive shaft 5 is rotated in the B direction in the figure, as shown in FIG.
, The rotational force is transmitted to the power output unit 10c, one end of the stopper unit 13 is pressed by the lever 11, and the shutter is released.
12 rotates and the other end of the stopper portion 13 rises.

FIG. 9 is a side view of the main part showing the operation of the lever, and 6b shows a hole formed on the surface of the document table 6 and at the portion where the other end of the stopper 13 opposes. As described above, the rotational force is not transmitted to the power output unit 10c when the document is fed, so that the stopper unit 13 is moved by the dead weight of the shutter 12 (or biased by the spring) as shown in FIG. 9A. In the lowered state, the other end of the stopper portion 13 is located below the hole 6b.

When the document is not being fed, the drive shaft 5 is used.
Is rotated by a specified amount in the reverse direction when the document is fed, and
As shown in FIG. 5, the shutter 12 is raised to cause the other end of the stopper portion 13 to project into the hole 6b. This protruding stopper portion 13
As a result, the leading edges of the set originals P are aligned.
At this time, the other end of the protruding stopper portion 13 is inclined in the feeding direction, so that the leading edge of the document P is in a state in which the upper document projects more than the lower document.

Next, a series of paper feeding operations of the first embodiment will be described.

FIG. 10 is a flow chart showing the flow of a series of paper feeding operations of the first embodiment.

When the main body of the apparatus is turned on (S1), it is first judged whether or not there is a document on the document table 6 (S1).
2). This determination is made based on the presence / absence of the output of the detection sensor (not shown) provided in the device, and when there is no output ((S2)
NO) Continuously monitor for output. When there is output
(YES in (S2)) Lower the pickup roller 3 (S3),
The drive motor 14 is started to rotate in the normal direction (S4), and the document feeding is started.

When the paper feeding operation is continued (YES in (S5)) and eventually there is no original on the original table 6, the detection sensor is used.
The output (not shown) is turned off (NO in (S5)), the state is detected, the drive motor 14 is stopped (S6), and the pickup roller 3 is raised (S7). In addition, the drive motor 14
Is rotated in the reverse direction (S8), and the shutter 12 is raised.
(S9). In this reverse rotation operation, the stopper portion 13 is used for the original table 6.
It continues until it protrudes upward (NO in (S9)). Then, after the stopper portion 13 projects above the document table 6 ((S9) YE
S), stop the drive motor 14 (S10), and wait until the next original is set (S11).

FIG. 11 is a plan view showing an essential part of the second embodiment of the present invention, and 17 shows a torque limiter constituted by a spring. In the second embodiment, the power input portion 10a of the first embodiment is fitted on the drive shaft 5 so as to be movable only in the circumferential direction, and one end of the torque limiter 17 is fixed to the power input portion 10a. The end is fixed to the drive shaft 5. When the one-way clutch rotates in the direction opposite to the direction in which the rotation is transmitted (direction D in the figure), the torque limiter
The 17 is wound so that the constituent springs are tightened.

When the one-way clutch is rotated in the direction for transmitting rotation to the power transmission section 10b (direction E in the figure), a certain constant torque is transmitted from the drive shaft 5 to the one-way clutch 10, The shutter 12 is lifted. in this case,
Since the force for holding the shutter 12 in the raised state follows the torque generated by the torque limiter 17, for example, the stopper portion 13 of the shutter 12 on the original table 6 is more than the torque generated by the torque limiter 17 by some means. If pressed by force, the stopper portion 13 is lowered into the document table 6. The shutter 12 is held in contact with the original table 6 by the torque generated by the torque limiter 17.

Further, when the one-way clutch 10 rotates in the direction E in the figure, the spring is tightened as described above, so that the torque from the drive shaft 5 to the one-way clutch 10 is equal to or more than the predetermined torque. Is transmitted. However, since the rotation is not transmitted from the power input unit 10a to the power transmission unit 10b, the rotation is not transmitted to the power output unit 10c.

FIG. 12 is a flow chart showing the flow of a series of paper feeding operations of the second embodiment. The paper feeding operation of the second embodiment is the same from the power-on (S1) to the pickup roller raising (S7) in the paper feeding operation of the first embodiment shown in FIG. And after raising the pickup roller 3
(S7), by rotating the drive motor 14 in the reverse direction by the specified amount
(S8), the stopper portion 13 is projected onto the original table 6, and the state in which the stopper portion 13 is projected by the urging force of the torque limiter 17 is maintained, and in this state, the next original is set to stand by (S9).

According to the present embodiment configured as described above,
When the drive shaft 5 is rotated in the forward direction in order to rotate the reverse roller 2 in the direction opposite to the paper feeding direction by the one-way clutch 10 provided on the drive shaft 5, only the drive shaft 5 is rotated. Further, when the drive shaft 5 is rotated in the opposite direction to raise the shutter 12, the lever 11 also rotates at the same time and presses the stopper portion 13. Thus, unlike the conventional example, the drive motor does not bear the load of the shutter drive system during document feeding, and the torque limiter and the like are not always slid during document feeding, so it is inexpensive and excellent in durability. A different configuration can be realized.

In particular, according to the configuration of the second embodiment, it becomes unnecessary to provide a detecting means for detecting whether or not the shutter 12 has been lifted when the drive motor 14 is rotated in the reverse direction at the end of document feeding, and the control of the drive system is simple. become. Further, when it is desired to retract the stopper portion 13 from the document table 6 at the time of maintenance such as document jam removal, it becomes possible to retract the stopper part 13 from the document table 6 by pressing the shutter 12 with a certain constant force, which improves the maintainability.

[0036]

According to the present invention configured as described above, the drive motor does not bear the load of the shutter drive system during sheet feeding, and the torque limiter or the like is constantly slid during sheet feeding. Since it is not present, an inexpensive and highly durable configuration can be realized. Also, set the sheet bundle
When the stack of sheets
Since the side that is holding
Reliably convey the sheets in contact with each other to the separating and conveying means side in order.
You can

Further, it becomes unnecessary to provide a detecting means for detecting whether or not the movement of the shutter has been completed at the time of reverse rotation of the drive motor at the end of sheet feeding, and the control of the drive system is simplified. Further , it becomes possible to retract from the table, which improves the maintainability.

[Brief description of drawings]

FIG. 1 is a side view showing an arrangement of rollers and gears according to a first embodiment.

FIG. 2 is a perspective view showing a configuration near a feed roller.

FIG. 3 is a perspective view showing a configuration near a reverse roller.

FIG. 4 is a perspective view showing the appearance of an automatic document feeder.

FIG. 5 is a perspective view showing a drive system according to the first embodiment.

FIG. 6 is a plan view showing the structure of the one-way clutch according to the first embodiment.

FIG. 7 is a plan view showing a state when the ratchet portion is meshed.

FIG. 8 is a plan view showing a state where the ratchet portion is disengaged.

FIG. 9 is a side view of the main part showing the operation of the lever.

FIG. 10 is a flowchart showing the flow of a series of paper feeding operations of the first embodiment.

FIG. 11 is a plan view showing a main part of a second embodiment of the present invention.

FIG. 12 is a flowchart showing a flow of a series of paper feeding operations of the second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Feed roller, 2 ... Reverse roller, 3 ... Pickup roller, 4 ... Idle gear, 5 ... Drive shaft, 5a ... Drive gear, 6 ... Original table, 6a, 6
b ... hole, 7 ... pickup bracket, 8 ... reverse roller bracket, 9 ... feed roller drive shaft,
10 ... One-way clutch, 10a ... Power input section, 10b ... Power transmission section, 10c ... Power output section, 10d ... Ratchet section,
10e ... Protrusion, 10f ... Sliding surface, 10g ... Locking part, 11 ...
Lever, 12 ... U-shaped shutter, 13 ... Stopper part,
14 ... Drive motor, 15 ... Feed gear, 16 ... Reverse gear, 17 ... Torque limiter.

Claims (2)

(57) [Claims] 1. A separating / conveying means for separating and feeding the sheets one by one from a bundle of sheets, and a separating / conveying means disposed upstream of the separating / conveying means in the sheet feeding direction and abutting the sheet. Pre-conveying means for conveying the sheet to the means,
A forward / reverse driving unit for driving the separating / conveying unit and a rotation transmission system for transmitting the rotation of the driving unit are provided, and the separating / conveying unit is driven to rotate the sheet when the driving unit is normally rotated. In a sheet separating device for separating and feeding, a side having an inclined surface that abuts on a leading end of the sheet bundle and a side of the sheet bundle that abuts on the preliminary conveying means is in a state of protruding in a sheet feeding direction. A device is provided which forms a stopper portion for inclining and aligning the tip of the sheet bundle.
A shutter provided rotatably on the main body, and drive transmission means for transmitting a driving force from the drive means to the shutter by connecting to the rotation transmission system only when the drive means rotates in the reverse direction are provided. The shatter can be
Rotate the motor by moving the stopper portion can contact positioned at the front end of the sheet bundle, to release the connection between the drive transmission means and the rotation transmission system by normal rotation of the drive means A sheet separating apparatus, wherein the shutter is returned to the state before the rotation, and the contact state between the stopper portion and the sheet bundle is released. Wherein when transmitting a driving force to said shutter from said drive transmitting means, a constant or more driving force is the Shah
Sheet separating apparatus according to claim 1, further comprising a driving force regulating means for regulating to be transmitted to the jitter.